I don’t think hisoka is French
I found on old Reddit subs many people who said that hisoka is French, I am French and i can say that his full name "hisoka morrow" is not French and does not sound French, and also togashi never say he was French so I wonder why people randomly assign countries to characters who have nothing to do with it
Edit: some people say because of the Latina dub, but he doesn’t have any accent on any other languages dub, also the Japanese dub is the original and he don’t have a French accent